The evaporation of water from the aerial parts of a plant is called transpiration.
Functions of transpiration:
(i) It helps in the upward movement of water and minerals from root to the aerial parts through the stem and in the absorption.
(ii) It helps in cooling the plant surface. It helps in the movement of dissolved minerals from root to leaves.
OR
(a) The transport of food from leaves to other parts of the plant is called translocation. Translocation is essential for plants because without it food prepared by the leaves cannot reach other parts of the plant for their growth and development.
(b) The substances in plants reach to other tissues in plants from the leaves, fruits, seeds and other growing organs as a result of translocation.